Is there a way to change the mortar geometry of the Brick Texture?
You can do something like this :



The Noise texture is used to distort the Vector input to the Brick Texture node - this results in distortion of the brick texture. Note how the Factor of the Add node (a MixRGB node set to 'Add') is extremely low and the Scale of the Noise texture increased to 75 to produce many small ripples in the lines of mortar.